APA (7th ed.) Citation

Hubble, E. (1937). Our sample of the universe. Carnegie institution of Washington.

Chicago Style (17th ed.) Citation

Hubble, Edwin. Our Sample of the Universe. Washington, D.C.: Carnegie institution of Washington, 1937.

MLA (9th ed.) Citation

Hubble, Edwin. Our Sample of the Universe. Carnegie institution of Washington, 1937.

Warning: These citations may not always be 100% accurate.